Games like RetroSpace
Games like RetroSpace include System Shock, Prey, Half-Life 2, Black Mesa, and BioShock Infinite. We matched them by the tags players give RetroSpace on Steam (Immersive Sim, Action, First-Person, Sci-fi, and Singleplayer): closest matches first, and among equally close ones the better-known games.

System Shock
Shared: Immersive Sim · Action · Sci-fi

Prey
Shared: Immersive Sim · Sci-fi · Singleplayer

Half-Life 2
Shared: Action · Sci-fi · FPS

Black Mesa
Shared: Action · Sci-fi · First-Person

BioShock Infinite
Shared: Action · First-Person · Singleplayer

Cyberpunk 2077
Shared: Singleplayer · Cyberpunk · Sci-fi

Deus Ex: Mankind Divided
Shared: Sci-fi · Action · Immersive Sim

RoboCop: Rogue City
Shared: Action · First-Person · Singleplayer

Deus Ex: Human Revolution - Director’s Cut
Shared: Sci-fi · Action · Cyberpunk

METRO Last Light Redux
Shared: Action · FPS · First-Person

Alien: Isolation
Shared: Sci-fi · Horror · First-Person

METRO 2033 Redux
Shared: Action · FPS · First-Person

Atomic Heart
Shared: Action · Adventure · Singleplayer

Metro Exodus
Shared: Singleplayer · Action · FPS

BioShock™
Shared: Action · FPS · Singleplayer

BioShock™ Remastered
Shared: FPS · First-Person · Action

BioShock™ 2 Remastered
Shared: Action · Singleplayer · FPS

Fallout 4
Shared: Singleplayer · Adventure · First-Person

Resident Evil Village
Shared: First-Person · Action · Singleplayer

Outlast
Shared: First-Person · Horror · Singleplayer

Half-Life: Alyx
Shared: FPS · First-Person · Action

Halo Infinite
Shared: Action · Singleplayer · First-Person

Deus Ex: Game of the Year Edition
Shared: Immersive Sim · Action · Cyberpunk

Dishonored
Shared: First-Person · Action · Singleplayer